Messages in this thread | | | Date | Tue, 20 Mar 2012 00:46:04 -0700 (PDT) | Subject | Re: [PATCH 1/2] clk: Fix error handling in fixed clock hardware type register fn | From | "Saravana Kannan" <> |
| |
On Tue, March 20, 2012 12:19 am, Sascha Hauer wrote: > On Mon, Mar 19, 2012 at 08:38:25PM -0700, Saravana Kannan wrote: >> If memory allocation for the parents array or the parent string fails, >> then >> fail the registration immediately instead of calling clk_register and >> hoping it fails there. >> >> Return -ENOMEM on failure. >> >> Signed-off-by: Saravana Kannan <skannan@codeaurora.org> >> Cc: Mike Turquette <mturquette@linaro.org> >> Cc: Andrew Lunn <andrew@lunn.ch> >> Cc: Rob Herring <rob.herring@calxeda.com> >> Cc: Russell King <linux@arm.linux.org.uk> >> Cc: Jeremy Kerr <jeremy.kerr@canonical.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: Arnd Bergman <arnd.bergmann@linaro.org> >> Cc: Paul Walmsley <paul@pwsan.com> >> Cc: Shawn Guo <shawn.guo@freescale.com> >> Cc: Sascha Hauer <s.hauer@pengutronix.de> >> Cc: Jamie Iles <jamie@jamieiles.com> >> Cc: Richard Zhao <richard.zhao@linaro.org> >> Cc: Saravana Kannan <skannan@codeaurora.org> >> Cc: Magnus Damm <magnus.damm@gmail.com> >> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> >> Cc: Linus Walleij <linus.walleij@stericsson.com> >> Cc: Stephen Boyd <sboyd@codeaurora.org> >> Cc: Amit Kucheria <amit.kucheria@linaro.org> >> Cc: Deepak Saxena <dsaxena@linaro.org> >> Cc: Grant Likely <grant.likely@secretlab.ca> >> --- >> There are still some memory free issues when clk_register() fails, but I >> will >> fix it when I fixed the other register() fns to return ENOMEM of alloc >> failure instead of a NULL. >> >> drivers/clk/clk-fixed-rate.c | 10 +++++++--- >> 1 files changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/clk/clk-fixed-rate.c b/drivers/clk/clk-fixed-rate.c >> index 90c79fb..6423ae9 100644 >> --- a/drivers/clk/clk-fixed-rate.c >> +++ b/drivers/clk/clk-fixed-rate.c >> @@ -61,22 +61,26 @@ struct clk *clk_register_fixed_rate(struct device >> *dev, const char *name, >> parent_names = kmalloc(sizeof(char *), GFP_KERNEL); >> >> if (! parent_names) >> - goto out; >> + goto fail_ptr; >> >> len = sizeof(char) * strlen(parent_name); >> >> parent_names[0] = kmalloc(len, GFP_KERNEL); >> >> if (!parent_names[0]) >> - goto out; >> + goto fail_str; >> >> strncpy(parent_names[0], parent_name, len); >> } > > It's easier to add a char *parent to struct clk_fixed and pass it to > clk_register with &fixed->parent. This saves you a kmalloc call and > makes the error path simpler. It's the same way already done in the > divider.
I thought about that since I saw the same was done for gated and divider (I think). Here is my guess at Mike's reasoning for this:
Gated and divider clocks have to have a parent. There's nothing to gate otherwise. But fixed rate clocks might not have a parent. It could be XO's or PLLs running off of always on XOs not controlled by the SoC. So, it's arguable to not have a parent. I don't have a strong opinion on this -- since Mike took the time to write it, it left it to his subjective preference.
I sent this patch first since it was around the place I was cleaning up. I didn't want to actually just shuffle around a bug. As I mentioned, this patch still leaves a bug open -- what if clk_register() fails. I plan to fix that once my two patches are picked up (hopefully).
Thanks, Saravana
-- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
| |